When booting to a graphical desktop, a text mode login prompt appears for a
short while before the graphical login screen shows up, with sddm and xdm at
least.
The reason is that the function plymouth_quit() is called before the
displaymanager is started so that plymouth doesn't block the VT.
That's the case at least with xdm, sddm, and lightdm; kdm and gdm handle
plymouth themselves...

This is mainly a cosmetical issue, but I also heard of users getting confused
and thinking they have to login to text mode to get to a graphical system
(because that's what they experienced: they logged in in text mode, and then
the graphical desktop started).

On the sddm side we are intending to improve things by calling "plymouth quit
--retain-splash" instead of plymouth_quit (in Factory/Tumbleweed only for now),
but the same change may be a good idea for the standard displaymanager script
too.

For the record, I tried xdm with that change and it started up fine here.